Add color user-font support

Adds new API cairo_user_font_face_set_render_color_glyph_func()
to set a color glyph renderer.

1 files changed, 251 insertions, 0 deletions

diff --git a/test/user-font-color.c b/test/user-font-color.c
new file mode 100644
index 000000000..437e57a27
--- /dev/null
+++ b/test/user-font-color.c
@@ -0,0 +1,251 @@
+/*
+ * Copyright © 2006, 2008 Red Hat, Inc.
+ * Copyright © 2021 Adrian Johnson
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of
+ * Red Hat, Inc. not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission. Red Hat, Inc. makes no representations about the
+ * suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * RED HAT, INC. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL RED HAT, INC. BE LIABLE FOR ANY SPECIAL,
+ * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+ * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Contributor(s):
+ *	Kristian Høgsberg <krh@redhat.com>
+ *	Behdad Esfahbod <behdad@behdad.org>
+ */
+
+/* Test that user-fonts can handle color and non-color glyphs in the
+ * same font.
+ */
+
+#include "cairo-test.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+
+
+#define BORDER 10
+#define TEXT_SIZE 64
+#define WIDTH  (TEXT_SIZE * 6 + 2*BORDER)
+#define HEIGHT (TEXT_SIZE + 2*BORDER)
+
+#define TEXT   "abcdef"
+
+
+static cairo_status_t
+test_scaled_font_init (cairo_scaled_font_t  *scaled_font,
+		       cairo_t              *cr,
+		       cairo_font_extents_t *metrics)
+{
+    metrics->ascent  = .75;
+    metrics->descent = .25;
+    return CAIRO_STATUS_SUCCESS;
+}
+
+static void
+render_glyph_solid (cairo_t *cr, double width, double height, cairo_bool_t color)
+{
+    if (color)
+        cairo_set_source_rgba (cr, 0, 1, 1, 0.5);
+    cairo_rectangle (cr, 0, 0, width/2, height/2);
+    cairo_fill (cr);
+
+    if (color)
+        cairo_set_source_rgba (cr, 1, 0, 1, 0.5);
+    cairo_rectangle (cr, width/4, height/4, width/2, height/2);
+    cairo_fill (cr);
+
+    if (color)
+        cairo_set_source_rgba (cr, 1, 1, 0, 0.5);
+    cairo_rectangle (cr, width/2, height/2, width/2, height/2);
+    cairo_fill (cr);
+}
+
+static void
+render_glyph_linear (cairo_t *cr, double width, double height, cairo_bool_t color)
+{
+    cairo_pattern_t *pat;
+
+    pat = cairo_pattern_create_linear (0.0, 0.0, width, height);
+    cairo_pattern_add_color_stop_rgba (pat, 0,   1, 0, 0, 1);
+    cairo_pattern_add_color_stop_rgba (pat, 0.5, 0, 1, 0, color ? 0.5 : 1);
+    cairo_pattern_add_color_stop_rgba (pat, 1,   0, 0, 1, 1);
+    cairo_set_source (cr, pat);
+
+    cairo_rectangle (cr, 0, 0, width, height);
+    cairo_fill (cr);
+}
+
+static void
+render_glyph_text (cairo_t *cr, double width, double height, cairo_bool_t color)
+{
+    cairo_select_font_face (cr, CAIRO_TEST_FONT_FAMILY " Sans",
+			    CAIRO_FONT_SLANT_NORMAL,
+			    CAIRO_FONT_WEIGHT_NORMAL);
+    cairo_set_font_size(cr, 0.5);
+
+    if (color)
+        cairo_set_source_rgb (cr, 0.5, 0.5, 0);
+    cairo_move_to (cr, width*0.1, height/2);
+    cairo_show_text (cr, "a");
+
+    if (color)
+        cairo_set_source_rgb (cr, 0, 0.5, 0.5);
+    cairo_move_to (cr, width*0.4, height*0.9);
+    cairo_show_text (cr, "z");
+}
+
+static cairo_status_t
+test_scaled_font_render_color_glyph (cairo_scaled_font_t  *scaled_font,
+                                     unsigned long         glyph,
+                                     cairo_t              *cr,
+                                     cairo_text_extents_t *metrics)
+{
+    cairo_status_t status = CAIRO_STATUS_SUCCESS;
+    double width = 0.5;
+    double height = 0.8;
+
+    metrics->x_advance = 0.75;
+    cairo_translate (cr,  0.125, -0.6);
+    switch (glyph) {
+        case 'a':
+            render_glyph_solid (cr, width, height, TRUE);
+            break;
+        case 'b':
+            render_glyph_linear (cr, width, height, TRUE);
+            break;
+        case 'c':
+            render_glyph_text (cr, width, height, TRUE);
+            break;
+        case 'd':
+            render_glyph_solid (cr, width, height, TRUE);
+            status = CAIRO_STATUS_USER_FONT_NOT_IMPLEMENTED;
+            break;
+        case 'e':
+            render_glyph_linear (cr, width, height, TRUE);
+            status = CAIRO_STATUS_USER_FONT_NOT_IMPLEMENTED;
+            break;
+        case 'f':
+            render_glyph_solid (cr, width, height, TRUE);
+            status = CAIRO_STATUS_USER_FONT_NOT_IMPLEMENTED;
+            break;
+    }
+
+    return status;
+}
+
+static cairo_status_t
+test_scaled_font_render_glyph (cairo_scaled_font_t  *scaled_font,
+			       unsigned long         glyph,
+			       cairo_t              *cr,
+			       cairo_text_extents_t *metrics)
+{
+    double width = 0.5;
+    double height = 0.8;
+    metrics->x_advance = 0.75;
+    cairo_translate (cr,  0.125, -0.6);
+    switch (glyph) {
+        case 'd':
+            render_glyph_solid (cr, width, height, FALSE);
+            break;
+        case 'e':
+            render_glyph_linear (cr, width, height, FALSE);
+            break;
+        case 'f':
+            render_glyph_text (cr, width, height, FALSE);
+            break;
+    }
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+static cairo_status_t
+_user_font_face_create (cairo_font_face_t **out)
+{
+
+    cairo_font_face_t *user_font_face;
+
+    user_font_face = cairo_user_font_face_create ();
+    cairo_user_font_face_set_init_func (user_font_face, test_scaled_font_init);
+    cairo_user_font_face_set_render_color_glyph_func (user_font_face, test_scaled_font_render_color_glyph);
+    cairo_user_font_face_set_render_glyph_func (user_font_face, test_scaled_font_render_glyph);
+
+    *out = user_font_face;
+    return CAIRO_STATUS_SUCCESS;
+}
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    cairo_font_face_t *font_face;
+    const char text[] = TEXT;
+    cairo_font_extents_t font_extents;
+    cairo_text_extents_t extents;
+    cairo_status_t status;
+
+    cairo_set_source_rgb (cr, 1, 1, 1);
+    cairo_paint (cr);
+
+    status = _user_font_face_create (&font_face);
+    if (status) {
+	return cairo_test_status_from_status (cairo_test_get_context (cr),
+					      status);
+    }
+
+    cairo_set_font_face (cr, font_face);
+    cairo_font_face_destroy (font_face);
+
+    cairo_set_font_size (cr, TEXT_SIZE);
+
+    cairo_font_extents (cr, &font_extents);
+    cairo_text_extents (cr, text, &extents);
+
+    /* logical boundaries in red */
+    cairo_move_to (cr, 0, BORDER);
+    cairo_rel_line_to (cr, WIDTH, 0);
+    cairo_move_to (cr, 0, BORDER + font_extents.ascent);
+    cairo_rel_line_to (cr, WIDTH, 0);
+    cairo_move_to (cr, 0, BORDER + font_extents.ascent + font_extents.descent);
+    cairo_rel_line_to (cr, WIDTH, 0);
+    cairo_move_to (cr, BORDER, 0);
+    cairo_rel_line_to (cr, 0, 2*BORDER + TEXT_SIZE);
+    cairo_move_to (cr, BORDER + extents.x_advance, 0);
+    cairo_rel_line_to (cr, 0, 2*BORDER + TEXT_SIZE);
+    cairo_set_source_rgb (cr, 1, 0, 0);
+    cairo_set_line_width (cr, 2);
+    cairo_stroke (cr);
+
+    /* ink boundaries in green */
+    cairo_rectangle (cr,
+		     BORDER + extents.x_bearing, BORDER + font_extents.ascent + extents.y_bearing,
+		     extents.width, extents.height);
+    cairo_set_source_rgb (cr, 0, 1, 0);
+    cairo_set_line_width (cr, 2);
+    cairo_stroke (cr);
+
+    /* text in color */
+    cairo_set_source_rgb (cr, 0, 0, 0);
+    cairo_move_to (cr, BORDER, BORDER + font_extents.ascent);
+    cairo_show_text (cr, text);
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+CAIRO_TEST (user_font_color,
+	    "Tests user font color feature",
+	    "font, user-font", /* keywords */
+	    "cairo >= 1.17.4", /* requirements */
+	    WIDTH, HEIGHT,
+	    NULL, draw)